Unit having contact protective means

ABSTRACT

CONTACT UNIT ADAPTED FOR INSERTION IN AN INTERNAL PASSAGE OF A CONNECTOR BODY AND INCLUDING A RESILIENT SPRING METAL CONTACT ENGAGEABLE WITH A MATING CONTACT AND SUBSTANTIALLY ENVELOPED WITHIN A PROTECTIVE HOUSING TO PREVENT DAMAGE THERETO. THE HOUSING, CONTACT AND TERMINAL MEANS ARE PREFERABLY INTEGRAL WITH A METAL BODY AND FORMED FROM A ONE-PIECE SHEET METAL STAMPING.

United States Patent Inventors Heinz Knitter Heilbronn; Josef Veszelik, Weinsberg, Germany Filed May 7,1969 Patented May 25, 1971 Assignee The Bunker-Kame Corporation Oak Brook, 11].

CONTACT UNIT HAVING CONTACT PROTECTIVE MEANS 8 Claims, 7 Drawing Figs.

US. Cl 339/176, 339/217, 339/256 Int. Cl HOlr 13/42 Field of Search 339/176, 252, 256, 217

[56] References Cit-ed UNITED STATES PATENTS 3,178,673 4/1965 Krehbiel 339/217 3,193,795 7/1965 KrehbieL... 339/217 3,365,694 1/1968 Parker 339/17 3,417,362 12/1968 Reynolds 339/17 Primary Examiner-Stephen J. Novosad Assistant Examiner-Joseph H. McGlynn Attorney-Frederick M. Arbuckle ABSTRACT: Contact unit adapted for insertion in an internal passage of a connector body and including a resilient spring metal contact engageable with a mating contact and substantially enveloped within a protective housing to prevent damage thereto. The housing, contact and terminal means are preferably integral with a metal body and formed from a onepiece sheet metal stamping.

PATENTED HAY25 197:

FIG. 4

SHEET 2 BF 2 INVENTORS HEINZ KNLTTER JOSEF VESZELIK ATTORNEYS CONTACT UNIT HAVING CONTACT PROTECTIVE MEANS This invention relates to a contact unit for an electrical connector and more particularly to a contact unit having a resilient contact element so supported that it cannot be damaged in transport, storage or handling. The unit is relatively simple and inexpensive in construction while being rugged and highly reliable.

The invention was evolved with the general object of overcoming the disadvantages of prior art contact units in which resilient contact elements are so supported that they are easily overstressed or otherwise damaged in transport, storage or in handling as during the attachment ofa connector wire thereto. As a result, broken or malfunctioning contact elements have been a common occurrence, especially when the units are handled by unskilled or negligent workers.

According to this invention, a contact unit is provided which is adapted to be supported in internal passage means of an insulating connector body and which includes protective means to prevent overstressing of a resilient spring metal contact element which is engageable with a mating contact in serted in the connector body. Preferably, the resilient contact has a rearward end portion connected to a metal body on which the protective means is disposed and a forward end portion for engagement with a mating contact element, the forward end portion being urged outwardly by the inherent resiliency of the contact element, and being deflectable inwardly by engagement by a mating contact element.

According to a specific feature of the invention, the protective means comprises a wall of the metal body disposed opposite the contact element in generally parallel relation thereto and in a position such as to limit inward deflection of the forward end portion.

According to another specific feature, the protective means further includes a pair of walls of the metal body disposed in spaced parallel relation along opposite sides of the contact element to limit sidewise deflection thereof.

Such walls preferably extend a substantial distance forwardly beyond the forward end portion of the contact element, and are all preferably formed integrally with the metal body.

Another specific feature is in the provision of stop means engageable by an intermediate portion of the contact element with the element being prestressed to engage the stop means with a certain force.

A further specific feature is in the formation of the contact element in a manner such as to provide a cam surface for engagement by a mating contact element and to provide smoothly rounded corners to further prevent damage to the element.

Additional features relate to the provision of terminal means on the contact unit for connection to a connecting wire to the provision of a stop and a resilient tab for releasably holding the contact unit in the connector body, and to the formation of the contact element, housing, metal body, terminal means and resilient tab from a one-piece sheet metal stamping.

This invention contemplates other objects, features and advantages which will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate a preferred embodiment and in which:

FIG. 1 is a side view of an electrical contact unit constructed according to the invention, shown installed in a connector body shown in cross section;

FIG. 2 is a perspective view of the contact unit;

FIG. 3 is a front view ofthe contact unit;

FIG. 4 is a sectional view on an enlarged scale, taken substantially along line [V-lV ofthe contact unit;

FIG. Sis a forward end view ofthe contact unit;

FIG. 6 is a rear view of the contact unit; and

FIG. 7 is a view showing the form of a sheet metal stamping used to form the contact unit, before bending.

Reference numeral 10 generally designates a contact unit constructed in accordance with the principles of this invention. The contact unit 10 comprises a metal body 1] having thereon a terminal 12 adapted to be connected to a connecting wire. The body H is adapted for insertion into a passage 13 of a connector body 14 which has a second passage 15 in generally parallel relation to the passage 13. The contact unit 10 includes a resilient spring metal contact element 16 having a rearward end portion [7 connected to the metal body 11 and having a forward end portion l8 which extends through a slot 19 between the passages l3 and I5 for engagement with a mating contact element 20 shown partially inserted into the passage 15. The end portion 18 is urged] outwardly to the posi tion shown in FIG. I by the inherent resiliency of the contact element 16 and is dcflectable inwardly by engagement by the mating contact element 20, to exert a certain contact force and to insure a good electrical connection.

According to this invention, protective means are provided on the metal body 11 for protecting the contact element 16 against overstressing. According to a specific feature, the protective means comprises a rear wall 22 disposed opposite the contact element 16 in generally parallel relation thereto and in a position such as to limit inward deflection of the end portion 18.

According to another specific feature, the protective means comprises a pair of walls 23 and 24 disposed in spaced parallel relation along opposite sides of the contact element 16 to limit sidewise deflection thereof. Preferably, the walls 22, 23 and 24 extend forwardly a substantial distance beyond the forward end of the contact element 16. It will be noted that the walls 22, 23 and 24 thus substantially envelope the contact element 16, with only the forward end portion 18 projecting therefrom.

The forward end portion 18 of the contact element 16 comprises a first section 26 extending angularly forwardly and outwardly, a second section 27 extending angularly forwardly and inwardly from the first section 26 and a third section 28 extending rearwardly from the second section 27 with a smoothly rounded comer 29 at the junction between sections 26 and 27 and with another smoothly rounded corner 30 at thejunction between the sections 27 and 28.

The section 27 provides a cam surface for engagement by the contact element 20 to cam the end portion 18 of the element l6 inwardly when the element 20 is inserted into the passage 15 and also serves to cam the end portion 18 inwardly when the unit 10 is installed in the passage 13. The portion 26 also defines a cam surface to cam the portion 18 inwardly when the unit 10 is withdrawn from the body 14. The sections 26 and 27 as well as the rounded corners 29 and 30 are also desirable as protective means in that the form thereof is such that the portion 18 cannot be readily hooked onto other contact units of the same construction, when a number of the units are placed loosely in a storage container.

Another feature of the unit 10 is in the provision of a stop 32 which is preferably formed as an inturned tab from the sidewall 23 and which is engageable by an intermediate portion 33 of the element 16, the portion 33 being preferably offset inwardly. The element [6 is preferably prestressed to engage the stop tab 32 with a certain force. By way of example, the element 16 may be prestressed in a manner such that without the stop tab 32, the element 16 would extend outwardly at an angle on the order of 5 so as to position the end portion as indicated in broken lines in FIG. 1

It is noted that a rigidifying rib 34 is preferably provided in the rearward end portion 17 of the element 16 and in the adjacent portion of a wall 35 of the housing 11 to increase the force with which the element 16 engages the stop tab 32 as well as to increase the force required to deflect the element in wardly.

The terminal 12 is formed as an integral extension of the wall 24 and comprises a pair of in-turmed portions 37 and 38 arranged to be crimped onto a connecting wire and another pair of portions 39 and 40 arranged to be crimped onto the insulating covering of the connecting wire. The forward end of the terminal l2 extends inwardly to define a stop surface 41 for engagement with a shoulder 42 in the passage 13 and a resilient tab extends integrally from the wall 22 to engage an oppositely facing shoulder 44, to retain the unit in the housing, the tab 43 being deflected inwardly when the unit is installed. To remove the unit, a tool 45 is inserted into a slot 46 formed along one side of the passage 13 to engage the tab 43 and to deflect it outwardly beyond the shoulder 44.

FIG. 7 shows the form of the unit 10 before it is bent into the condition shown in FIGS. l-6, the approximate location of the required bends being indicated in dotted lines. It will he appreciated that .the unit can thus be formed readily as a onepiece sheet metal stamping which is then bent to obtain the configuration shown.

This invention thus provides a. contact unit in which a resilient spring metal contact is substantially enveloped within a protective housing to prevent damage thereto and it will be appreciated that it can be readily and inexpensively manufactured while being rugged and reliable in operation.

We claim:

1. A contact unit for an electrical connector including a insulating body having first and second parallel passages therein and a separating wall between said passages having a slot therein, said contact unit being insertable into said first passage and comprising integrally connected sheet metal walls including a pair of sidewalls and a front wall, said front wall being disposed adjacent said separating wall of said insulating body, a contact element having a rearward end portion integrally connected to said front wall and having a forward end portion adapted to project through said slot and into said second passage for engagement by a mating contact element in said second passage.

2. A contact unit as defined in claim 1, further including a rigidifying rib in said rearward end portion ofsaid contact element and in the adjacent portion of said front wall.

3. A contact unit as defined in claim 1, further including a rear wall disposed opposite said front wall andjoining said pair of sidewalls. v

4. A contact unit as defined in claim 3, further including a resilient locking tab extending from one of said walls and engaging a shoulder on said insulating body to retain said contact unit in said first passage.

5. A contact unit as defined in claim 4, wherein said locking tab extends from and is integrally connected to said rear wall.

6. A contact unit as defined in claim 5, wherein said insulating body further includes another passage extending to said shoulder for receiving a tool to release said locking tab so that said contact unit can be withdrawn from said first passage.

7. A contact unit as defined in claim 5, further including a stop tab extending from one of said sidewalls and engageable by said contact element to limit the movement of said contact element in projecting through said slot.

87 A contact unit as defined in claim 7, said forward end portion of said contact element comprising a first section extending angularly forwardly and outwardly, a second section extending angularly forwardly and inwardly from said first section, a third section extending rearwardly from said second section with smoothly rounded corners at the junction between said first and second sections and at the junction between said second and third sections, and a fourth section joining said first section and said rearward end portion for engaging said stop tab. 

2. A contact unit as defined in claim 1, further including a rigidifying rib in said rearward end portion of said contact element and in the adjacent portion of said front wall.
 3. A contact unit as defined in claim 1, further including a rear wall disposed opposite said front wall and joining said pair of sidewalls.
 4. A contact unit as defined in claim 3, further including a resilient locking tab extending from one of said walls and engaging a shoulder on said insulating body to retain said contact unit in said first passage.
 5. A contact unit as defined in claim 4, wherein said locking tab extends from and is integrally connected to said rear wall.
 6. A contact unit as defined in claim 5, wherein said insulating body further includes another passage extending to said shoulder for receiving a tool to release said locking tab so that said contact unit can be withdrawn from said first passage.
 7. A contact unit as defined in claim 5, further including a stop tab extending from one of said sidewalls and engageable by said contact element to limit the movement of said contact element in projecting through said slot.
 8. A contact unit as defined in claim 7, said forward end portion of said contact element comprising a first section extending angularly forwardly and outwardly, a second section extending angularly forwardly and inwardly from said first section, a third section extending rearwardly from said second section with smoothly rounded corners at the junction between said first and second sections and at the junction between said second and third sections, and a fourth section joining said first section and said rearward end portion for engaging said stop tab. 